Tarantulas and Trapdoor Spiders: The Not-So-Terrible Truth

Tarantulas and Trapdoor Spiders: The Not-So-Terrible Truth

With the recent rainfall and onset of cooler temperatures, many San Antonio neighborhoods are seeing an increase of arachnids in their gardens.

Late summer and fall in San Antonio marks a time when cooler temperatures filter in, beautiful days with high skies bring smiles to our faces, and the tarantulas and trapdoor spiders go roaming for food and mates. Wait? What? How did this go from beautiful, crisp and cool, to dark, hairy and creepy?

With the increase in recent rainfall and onset of some cooler temperatures, many local San Antonio neighborhoods are seeing an increase in the appearance of Texas brown tarantulas (Aphonopelma hentzi) and a local trapdoor spider called Ummidia.

But fear not. Both of these spiders are welcome predators in the landscape, feeding on cockroaches, grasshoppers, crickets, small mammals, other spiders and generally anything smaller than they are.

The males of both species go roaming for mates and will also appear on the surface in response to being flooded out of their burrows.

Texas Brown Tarantula

Texas Brown Tarantulas grow up to 4 inches across and are covered with stiff, bristly hairs. They have brown bodies and black abdomens and are generally considered to be harmless. Their bite can be painful, but isn’t considered medically important.

When threatened, tarantulas break the stiff, urticating hairs off of their abdomens by rubbing them with their hind legs and flicking the loose hairs at the potential threat. These hairs are very irritating to the eyes like fiberglass.

They can be kept as pets and females have been documented to live for up to 30 years in captivity, with males only surviving two or three years.

Female Trapdoor Spider

Trapdoor spiders are a little more secretive in their habits. They build silken tunnels in soft soil and close them with a lid of soil held together with silk. Trapdoor spiders reach 3 inches across and have black, shiny bodies with hairy legs. The slightly smaller males rear up on their hind legs, exposing their fangs to perceived threats. Like tarantulas, the bite of these spiders is painful, but not considered medically important.

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Nathan Riggs

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Nathan Riggs

Nathan Riggs is a SAWS project coordinator and licensed irrigator who also happens to have a degree in entomology from Texas A&M University. Yes, Nathan’s a bug expert, and not just on water bugs! When he’s not hard at work on SAWS conservation projects, he enjoys a wide variety of interests including: landscaping, hiking, photography of flowers, insects and other critters, and planning his next adventure with his son, John, and daughter, Olivia.